I got a call today on a Williams Gas Heater mod.# 3501912.
Bad thermocouple.
This is not a common brand heater in my area.
I am unfamiliar with the procedure to access the thermocouple for replacement.
Does anyone here work on this model/brand of heater and can suggest the correct way to remove the thermocouple.
If you know this heater you know what I am talking about to get a wrench on the thermocouple.

No it is not a standard thermocouple. It has a damper sensor made into the thermocouple.
I have the thermocouple.
The problem had to do with accessing the pilot assembly to change the thermocouple.
I got it done.
Had to remove the gas valve,the burner,then remove the gas lines from the valve and burner just to get the thermocouple pilot assembly were it would clear the heat exchanger just enough to remove the thermocouple.
Any other heater it is a 15 minute job.
This one took 2 hours.
BUT. It is done and working good.
If I had to do another like it,I could do it in an hour and 45 minutes.

Just tried to look up the model number of the heater at sears without any luck. Tried to look up a photo of the thermocouple in you mentioned without success. Do you have the part number? I have seen thermocouples with junction blocks on them; this thermocouple must be something new.

Jumpy the part you listed is a junction block thermocouple. The thang that they talking about is obsolete and I never heard of it or even seen one so that tells me it was probably crappy design to begin with. Usually the p322391 connects to a fuse that looks like this: